Add detailed plan info and additional subscription types

Implemented detailed pricing information for various subscription types in the plan-picker component. Two additional subscription types, 'per-seat' and 'metered', have been added to the billing configuration, providing more flexibility for customers to choose different billing methods that suit their needs. The billing schema has also been refined to allow plans without a 'base' line item.

apps/web/config/billing.config.ts

@@ -28,6 +28,22 @@ export default createBillingSchema({
               cost: 9.99,
               type: 'base',
             },
+            {
+              id: 'price_1NNwYHI1i3VnbZTqI2UzaHIe6',
+              name: 'Per Seat',
+              description: 'Add-on plan',
+              cost: 1.99,
+              type: 'per-seat',
+            },
+            {
+              id: 'price_1NNwYHI1i3VnbZTqI2UzaHIe7',
+              name: 'Metered',
+              description: 'Metered plan',
+              cost: 0.99,
+              type: 'metered',
+              unit: 'GB',
+              included: 10,
+            },
           ],
         },
         {